Hello,
On R-Car H3 ES2.0+ and M3-N SoCs, two display pipelines are served by the same VSP instance (named VSPDL). The VSPDL includes two blending units named BRU and BRS, unlike the other display-related VSPD that serves a single display channel with a single blending unit.
The VSPDL has five inputs and can freely assign them at runtime to two display pipelines, using the BRU and BRS to blend multiple inputs. The BRU supports blending up to five inputs, while the BRS is limited to two inputs.
Each display pipeline requires a blending unit, and the BRU and BRS are currently assigned statically to the first and second pipeline respectively. This artificially limits the number of inputs for the second pipeline to two. To overcome that limitation, the BRU and BRS need to be dynamically assigned to the display pipelines, which is what this patch series does.
Patches 01/15 to 10/15 perform small cleanups and refactoring to prepare for the rest of the series. Patches 11/15 and 12/15 implement new internal features for the same purpose, and patch 13/15 performs the bulk of the work by implementing dynamic BRU and BRS assignment to pipelines.
Reassigning the BRU and BRS when two pipelines are running results in flicker as one pipeline has to first release its blending unit. Synchronization between the two pipelines also require locking that effectively serializes page flips for the two pipelines, even when not interacting with each other. This is currently believed to be unavoidable due to the hardware design, but please feel free to prove me wrong (ideally with a patch - one can always dream).
Patch 14/15 then adds messages useful for debugging this new feature. I have kept it separate from 13/15 to make it easier to remove those messages once dynamic assignment of blending units will be deemed perfectly stable, but I won't oppose squashing it with 13/15 if that is preferred.
Patch 15/15 finally rename BRU to BRx to avoid confusion between the BRU terms that refer to the BRU in particular, and the ones that refer to any of the BRU or BRS. As this might be a bit controversial I've put the patch last in the series in case it needs to be dropped.
I have decided to CC the dri-devel mailing list even though the code doesn't touch the R-Car DU driver and will be merged through the Linux media tree as the display is involved and the series could benefit from the expertise of the DRM/KMS community from that point of view.
The patches are based on top of the latest Linux media master branch. For convenience their are available from
git://linuxtv.org/pinchartl/media.git v4l2/vsp1/bru-brs
The series passes the DU test suite with the new BRx dynamic assignment test available from
git://git.ideasonboard.com/renesas/kms-tests.git bru-brs
The VSP test suite also runs without any noticed regression.
Laurent Pinchart (15): v4l: vsp1: Don't start/stop media pipeline for DRM v4l: vsp1: Remove outdated comment v4l: vsp1: Remove unused field from vsp1_drm_pipeline structure v4l: vsp1: Store pipeline pointer in vsp1_entity v4l: vsp1: Use vsp1_entity.pipe to check if entity belongs to a pipeline v4l: vsp1: Share duplicated DRM pipeline configuration code v4l: vsp1: Move DRM atomic commit pipeline setup to separate function v4l: vsp1: Setup BRU at atomic commit time v4l: vsp1: Replace manual DRM pipeline input setup in vsp1_du_setup_lif v4l: vsp1: Move DRM pipeline output setup code to a function v4l: vsp1: Add per-display list completion notification support v4l: vsp1: Generalize detection of entity removal from DRM pipeline v4l: vsp1: Assign BRU and BRS to pipelines dynamically v4l: vsp1: Add BRx dynamic assignment debugging messages v4l: vsp1: Rename BRU to BRx
drivers/media/platform/vsp1/Makefile | 2 +- drivers/media/platform/vsp1/vsp1.h | 6 +- .../media/platform/vsp1/{vsp1_bru.c => vsp1_brx.c} | 202 ++--- .../media/platform/vsp1/{vsp1_bru.h => vsp1_brx.h} | 18 +- drivers/media/platform/vsp1/vsp1_dl.c | 27 +- drivers/media/platform/vsp1/vsp1_dl.h | 4 +- drivers/media/platform/vsp1/vsp1_drm.c | 829 ++++++++++++--------- drivers/media/platform/vsp1/vsp1_drm.h | 16 +- drivers/media/platform/vsp1/vsp1_drv.c | 8 +- drivers/media/platform/vsp1/vsp1_entity.h | 2 + drivers/media/platform/vsp1/vsp1_histo.c | 2 +- drivers/media/platform/vsp1/vsp1_histo.h | 3 - drivers/media/platform/vsp1/vsp1_pipe.c | 50 +- drivers/media/platform/vsp1/vsp1_pipe.h | 7 +- drivers/media/platform/vsp1/vsp1_rpf.c | 12 +- drivers/media/platform/vsp1/vsp1_rwpf.h | 4 +- drivers/media/platform/vsp1/vsp1_video.c | 37 +- drivers/media/platform/vsp1/vsp1_wpf.c | 8 +- 18 files changed, 705 insertions(+), 532 deletions(-) rename drivers/media/platform/vsp1/{vsp1_bru.c => vsp1_brx.c} (63%) rename drivers/media/platform/vsp1/{vsp1_bru.h => vsp1_brx.h} (66%)